The purpose of the Cardiac and Myocyte Physiology Core D is to provide required methods for the evaluation of the effects of glycoconjugate modifications on myocyte, muscle fiber, and intact heart physiology. Two in vitro methods and two non-invasive in vivo methods are employed. For Projects 1, 2 and 3, we will use isolated adult myocytes to determine the impact of protein modification on sarcomere shortening and relaxation, and on the whole cell calcium transient. Resting and adrenergic stimulated cells are studied. Myocyte isolation from adult heart models also are provided to the project for molecular studies and for the isolation of mitochondria. For Projects 2 and 3 we will provide isolated heart Langendorff preparations, to define organ function, and to provide tissue for additional analysis using models of ischemia/reperfusion and preconditioning. For Projects 1 and 5, the Core will determine cardiac function using non-invasive echo-Doppler imaging analysis over a fime-line for the animal models used. Mouse models of atherosclerosis on varying diets are a major focus of this analysis. Lastly, for Projects 2 and 3, we will determine vascular properties such as large artery stiffness using Doppler imaging of aortic flow at two locations and determination of pulse wave velocity. We have a wide variety of state-of-the-art methods to evaluate cardiac functions and some of the specific studies will be determined by the inifial data obtained.